An integer overflow flaw, leading to a heap-based buffer overflow, was found in the way grep parsed large lines of data. An attacker able to trick a user into running grep on a specially crafted data file could use this flaw to crash grep or, potentially, execute arbitrary code with the privileges of the user running grep. (CVE-2012-5667)A heap-based buffer overflow flaw was found in the way grep processed certain pattern and text combinations. An attacker able to trick a user into running grep on specially crafted input could use this flaw to crash grep or, potentially, read from uninitialized memory. (CVE-2015-1345)